How to do Time Value of Money on a Ti-83 Plus

This post, while not particularly relevant to things I normally write on here is something I felt necessary to write. In this post I will explain how to do time value of money (TVM) calculations on a Ti-83 Plus (which I assume is same for a Ti-83). The reason being, I find it ridiculous that finance professors ask you to purchase an entirely different calculator after most every student (at least for business) has already purchased an expensive Ti-83 for calculus. I am doing this in hopes of saving at least a few college students the $30 that the new calculator would cost. May those of you who saved the $30 use it on something interesting… like on your girlfriend (or your next date), a healthy dinner (for once), a ridiculously priced text-book, or to continue to feed your drinking problem.

How to do TVM on a Ti-83 Plus

Firstly, get familiar with the following process:

1. Turn on your calculator
2. Press “Apps”
3. Press “Finance”
4. Press “TVM Solver”

The TVM Solver is the place where you will always be going to to enter in the values for your calculation. That said, you will see the following variables when you go to the TVM Solver.

N = # of years.
I% = The % interest (or discount if you’re receiving money you) you are expecting.
PV = Initial Investment (this number should be negative if you are investing, as you’re giving your investing your money).
FV = Future value
PMT = Number of payments per period (period set below).
P/Y = Periods per year (should generally be one).
BEGIN = You should have your Ti-83 be on “END” by default, but you will want to change it to begin when dealing with annuity due.
END = You want to have this set when dealing with ordinary annuity.

Examples of using TVM Solver to do financial calculations

Now you know a little about what those numbers mean. Let’s take a look at what numbers we put where to do what.

Question 1:
We want to invest $1000 today and want it to be $5000 10 years from now. What is the interest rate we need to accomplish this?

To calculate this we will go to TVM Solver (Apps -> Finance -> TVM Solver) and set the listed variables to the following:

N = 10
I% = 0 (because we don’t know what the interest rate is)
PV = -1000 (negative 1000 because that’s how much we’re investing)
PMT = 0 (no additional payments being paid / period )
FV = 5000 (this is how much we want to have by the end of 10 years)
P/Y = 1

After entering in all that, hid “2nd” then “Mode” to take you back to your main display screen. Next, press “Apps”, “Finance” and then from the list find “TVM_I%” and press it.
Your result should be 17.46%
This means that if you invest $1000 today and want $5000 in 10 years from now, the interest rate you must have is 17.46%.

Question 2:
What must I invest now at 8% to get $5000 10 years from now?

Setting up our variables in TVM_Solver again:

N = 10 (10 years)
I% = 8 (enter whole numbers, TVM Solver converts it to .08 for you)
PV = 0 (0 because we want to know how much to invest to get $5000)
PMT = 0 (no additional payments being paid / period )
FV = 5000 (this is how much we want to have by the end of 10 years)
P/Y = 1

After entering in all that, hid “2nd” then “Mode” to take you back to your main display screen. Next, press “Apps”, “Finance” and then from the list find “TVM_PV” and press it.
Your result should be -2315.96
This means that if you invest (so you’re investing, thus no longer in your position, which is why it’s negative) $2315.96 today at 8%, in 10 years you will have $5000.

Basically the way it works is everything under “TVM_Solver” in the Apps -> Finance section of your calculator is a function that does a calculation based off of the values entered in TVM_Solver. So, to calculate something like the number of payments necessary, you’d fill in the necessary data in TVM_Solver, setting PMT to 0, and then running TVM_PMT.

Hope this helps some people. Feel free to comment to this with any questions.